A terror suspect who escaped surveillance by changing into a burka on a visit to a mosque has connections to the al Qaeda-linked al Shabaab Islamist group in Somalia, according to Sky sources.

Mohammed Ahmed Mohamed, who is 5ft 8in tall and of medium build and was last seen at a west London mosque on Friday afternoon, is being hunted by counter-terrorism officers.

He entered the An-Noor Masjid and Community Centre in Church Road, Acton, at 10am, wearing Western-style clothes, but CCTV images issued by Scotland Yard later showed him leaving with his face and body fully covered by the traditional Islamic garment.

The venue - where he was last seen at 3.15pm the same day - has said it does not intend to comment on the matter.

Image Caption:Mohamed is not considered a "direct threat", police said.

He was put under surveillance measures due to his connection with the Somalian terror group, which was behind the attack on Westgate Mall in the Kenyan capital Nairobi on September 21 that killed at least 67 people.

The 27-year-old is understood to have received terrorist training in 2008 and fought overseas for al Shabaab.

He is also also suspected of helping to plan attacks in Somalia and overseas, including an attack intended for the Juba Hotel in Mogadishu in August 2010, and is believed to have helped various individuals travel from the UK to Somalia to allow them to engage in terrorism-related activity.

A court-imposed anonymity order banning the publication of Mohamed's name has been lifted to allow police to make a public appeal, following an application from Home Secretary Theresa May.

He is the second person to breach a Tpim since they were introduced to replace control orders in early 2012.

Last December, Ibrahim Magag, who is understood to have attended terrorist training camps in Somalia, absconded from a Tpim notice after ripping off his electronic tag. The police search for him is continuing.

Court documents have revealed Mohamed helped support a UK-based network for terrorism-related activity in Somalia, which included Magag among its members.

The network had access to money, false passports and documentation, as well as equipment, with Mohamed being involved in fundraising for terrorism-related activity.

Between 2008 and late 2010, Mohamed is also understood to have procured weapons for terrorism uses.

Pressure has been mounting on the Government to explain how the al Qaeda-linked terror suspect escaped surveillance.

Mrs May said he posed "no direct threat to the public" and was placed on a Tpim to "prevent his travel to support terrorism overseas".

Making a statement in the House of Commons on his disappearance to MPs, she insisted the police and security service had "all the resources and the support they need to carry out this manhunt".

"However, I will not hesitate to provide them with any additional assistance they require," she added.

But former home secretary Jack Straw said she had "failed to protect the safety and security of the British people" by "acting so irresponsibly in weakening the powers available to control terrorists".

Shadow home secretary Yvette Cooper, who has described the matter as "extremely serious", also accused Mrs May of making it "easier for serious terror suspects to disappear".

"She was warned about changing the law, she was warned about weakening controls, she was warned more people would abscond - and they have, twice – and still she won't act," she said.

Video:Labour Wants Control Order Answers

Scotland Yard has urged anyone who sees the suspect to call 999 immediately.

"Ports and borders were notified with his photograph and details circulated nationally. Public safety remains our priority."

Prime Minister David Cameron's official spokesman said finding the suspect remained a "priority".

"Obviously, in all of these types of things, we look at whether there are lessons that can be learnt. But the reasons why the Government introduced the Tpim regime remain the same and the Prime Minister's view about Tpims haven't changed," he said.

Tpims, which include restrictions on overnight residence, travel and finance, are imposed by the Home Secretary who is given access to secret evidence that can not be placed before juries.

They do not allow for the relocation of suspects, as control orders did and unlike control orders, Tpims have a maximum time limit of two years.

Control orders could be extended year on year without limit, while Tpims can be extended after a year for another 12 months before they expire.

As of August 31, there were nine Tpims in force, including eight against British suspects, the latest written update to MPs showed.

The terrorism watchdog warned earlier this year that Tpims could allow those deemed potentially dangerous to be left "free and unconstrained" in the absence of prosecution or new evidence of terrorism-related activity.

David Anderson QC, the independent reviewer of terrorism legislation, said in his first report on Tpims, that the two-year limit was the "boldest" change from control orders made by the Government, adding that it was "tempting, in the most serious cases, to wish for longer".

However, he concluded that the two years of constraint now permitted were "a very strong power by international or indeed historic British standards".

Mr Brokenshire has defended the measures, describing them as providing a "robust mechanism" to manage suspects and reassure the public.

:: Watch Home Secretary Theresa May's statement to the Commons Live on Sky News at 3.30pm